Ceiling-type display position adjusting device link employing gear structure

ABSTRACT

Provided is a ceiling type display position adjusting device which employs a gear structure and enables a display to be positioned above the ceiling when the display is not watched to descend from the ceiling when the display is watched and even automatically adjusts a watching angle. The display position adjusting device includes: a body having a hollow shape having an opened lower portion and arranged above a ceiling; a retaining bracket retaining the body; a sliding member that is mounted inside the body and slidable downward below the ceiling; an elevating member sliding the sliding member downward below the body; supports coupled under the sliding member on both, left and right sides; a main link having a rear portion rotatably coupled between the supports via a hinge shaft and a front portion at which a display is mounted; and an angle adjusting unit rotating the main link about the hinge shaft to adjust an angle of the display, wherein the elevating member slides the sliding member in the body in a vertical direction to locate the display above or below the ceiling, and the angle adjusting unit rotates the main link that is moved below the ceiling via the elevating member to adjust a watching angle of the display.

TECHNICAL FIELD

The present disclosure relates to a ceiling-type display positionadjusting device employing a gear structure, and more particularly, to aceiling-type display position adjusting device which employs a gearstructure and enables a display that is positioned above the ceilingwhen the display is not watched to descend from the ceiling when thedisplay is watched, and automatically adjusts a watching angle.

BACKGROUND ART

In general, a display, that is, a TV, is placed indoors at a positionand watched.

Such display occupies one part of a space regardless of whether it iswatched or not.

Recently, a display has been installed and used on a wall or a ceilingto be able to increase and actually increase the space use rate.

In particular, a display fixing device for hanging a display on aceiling, which can be installed on the ceiling, has been developed.

FIG. 1 is a structural diagram of a ceiling-hanging type display fixingdevice according to the related art.

As illustrated in FIG. 1, the ceiling-hanging type display fixing deviceaccording to the related art includes a ceiling-attaching bracket 12;support rods 16 and 18 installed under the ceiling-attaching bracket andhaving variable lengths; an adjustment bracket 22 connected to thesupport rods and adjusted in left and right angles; a device-attachingbracket 24 coupled to the adjustment bracket; a pair of bracketconnection plates 26 attached at a certain position of the attachingbracket; a bracket 32 for an angle adjustment screw, the bracket beingcoupled to the bracket connection plates; an angle adjustment plate 30formed on the bracket connection plates and installed to abut on anouter circumference of the bracket for an angle adjustment screw; and anangle adjustment screw 34 pressurizing the angle adjustment plateagainst the angle adjustment screw bracket by closely adhering the angleadjustment plate.

However, in the ceiling-hanging type display fixing device according tothe related art, a position of a display has to be adjusted or awatching angle is to be adjusted manually, and also, the display isalways exposed indoors.

DESCRIPTION OF EMBODIMENTS Technical Problem

Provided is a ceiling-type display position adjusting device whichemploys a gear structure and enables a display that is positioned abovethe ceiling when the display is not watched to automatically descendfrom the ceiling when the display is watched, and automatically adjustsa watching angle of the display.

Solution to Problem

According to an aspect of the present disclosure, a ceiling-type displayposition adjusting device employing a gear structure includes: a bodyhaving a hollow shape having an opened lower portion and arranged abovea ceiling; a retaining bracket retaining the body; a sliding member thatis mounted inside the body and slidable downward below the ceiling; anelevating member sliding the sliding member downward below the body;supports coupled under the sliding member on left and right sides; amain link having a rear portion rotatably coupled between the supportsvia a hinge shaft and a front portion at which a display is mounted; andan angle adjusting unit rotating the main link about the hinge shaft toadjust an angle of the display, wherein the elevating member slides thesliding member in the body in a vertical direction to move the displayabove or below the ceiling, and the angle adjusting unit rotates themain link that is moved below the ceiling via the elevating member toadjust a watching angle of the display.

Also, the angle adjusting unit may include: a rotational motor; a wormrotated via the rotational motor; a worm gear that is engaged with theworm; a driving gear that is mounted on a same axis as the worm gear tobe rotated with the worm gear; and a driven gear that is mounted on anouter circumference at the rear portion of the main link, which ishinge-coupled to the supports, so as to be engaged with the drivinggear, wherein when the rotational motor is rotated, a rotation rate ofthe driving gear is reduced via the worm and the worm gear, and thedriven gear engaged with the driving gear is rotated accordingly, andthe angle adjusting unit rotates the rear portion of the main link abouta hinge shaft to thereby adjust an angle of the display mounted at thefront portion of the main link and protruding below the ceiling.

Also, the ceiling-type display position adjusting device may furtherinclude a cover member having a cut-off portion allowing the main linkto protrude and thus be rotatable, the cover member being mounted at alower portion of the sliding member to surround the supports and theangle adjusting unit.

Also, the elevating member may include: a lead screw, an upper end ofwhich is rotatably coupled inside the body; an elevating unit coupled toan upper end of the sliding member to move up and down in a verticaldirection by rotation of the lead screw; and a main motor rotating thelead screw, wherein when the main motor is rotated, the lead screw isrotated, and as the elevating unit moves up and down along the leadscrew, the sliding member slides in a vertical direction to move thedisplay upwardly or downwardly with respect to the ceiling.

Also, the ceiling-type display position adjusting device may furtherinclude a protection tube having a hollow shape into which the leadscrew is inserted, wherein one side of the protection tube is mounted onthe elevating unit and the other side of the protection tube is mountedat the lower portion of the sliding member such that the protection tubeis moved up and down along with the elevating unit to surround the leadscrew protruding below the elevating unit.

Also, a plurality of sliding grooves may be vertically formed in thebody, and a plurality of coupling holes may be formed in the slidingmember along the sliding grooves, and the ceiling-type display positionadjusting device may further include a sliding projection that isinserted into and coupled to each of the coupling holes to slide alongthe sliding grooves, wherein the sliding projection includes: a slidingportion protruding from the sliding member to slide along the slidinggrooves and including an inclined surface that is inwardly titled froman external surface thereof at an edge of an outer circumferencethereof; and a coupling portion protruding from the sliding portion tobe coupled to the coupling holes and having a protrusion at an end ofthe coupling portion, wherein the protrusion is inserted into thecoupling holes and caught on an outer circumference of the couplingholes.

Advantageous Effects of Disclosure

As described above, according to the ceiling-type display positionadjusting device of the present disclosure, which employs a gearstructure, following effects are obtained.

First, via the elevating member and the angle adjusting unit, when adisplay is not watched, the display is maintained above the ceiling, andwhen the display is watched, the display automatically descends from theceiling to allow watching and the watching angle of the display isautomatically adjusted.

Secondly, via the angle adjusting unit consisting of the worm and theworm gear, the rotational motor is made to move slowly by reducing arotation rate of the rotational motor and a change in the watching angleof the display occurring during a reverse rotation of the rotationalmotor, that is, when the rotational motor is stopped due to the weightof the display, is prevented.

By configuring the cover member as described above, the rear of each ofthe angle adjusting unit, the supports, and the main link includedtherein are not exposed, thereby maintaining the aesthetic sense andminimizing penetration of foreign substances.

By configuring the elevating member to include the lead screw, theelevating unit, and the main motor, installation may be easilyperformed, and the display may be easily moved above or below theceiling.

As the protection tube surrounds the lead screw protruding below theelevating unit, lubrication oil coated on the lead screw may beprevented from falling to the outside and piling of foreign substancesmay be prevented.

By configuring the sliding projection including the sliding portion andthe coupling portion as described above, as a plurality of slidingprojections are included, resistance due to friction occurring duringsliding of the sliding member may be minimized, and when the slidingportion of the sliding projection is worn out by friction, the slidingportion may be easily replaced by using the coupling portion.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a structural diagram of a ceiling-hanging type display fixingdevice, according to the related art.

FIG. 2 is a perspective view of one side of a ceiling protruding-typedisplay position adjusting device according to an embodiment of thepresent disclosure.

FIG. 3 is a side cross-sectional view illustrating a structure andoperation of an elevating member of a ceiling protruding-type displayposition adjusting device according to an embodiment of the presentdisclosure.

FIG. 4 is an exemplary view illustrating a display being moved by anelevating member of a ceiling protruding-type display position adjustingdevice according to an embodiment of the present disclosure.

FIG. 5 is a perspective view of the other side of a sliding member slidfrom a body in a ceiling protruding-type display position adjustingdevice according to an embodiment of the present disclosure.

FIG. 6 is a bottom perspective view showing an angle adjusting unit of aceiling protruding-type display position adjusting device according toan embodiment of the present disclosure.

FIG. 7 is a side cross-sectional view illustrating a structure andoperation of an angle adjusting unit of a ceiling protruding-typedisplay position adjusting device according to an embodiment of thepresent disclosure.

FIG. 8 is an exemplary view illustrating a display being moved by anangle adjusting unit of a ceiling protruding-type display positionadjusting device according to an embodiment of the present disclosure.

FIG. 9 is a perspective view illustrating a structure of a cover memberin a ceiling protruding-type display position adjusting device accordingto an embodiment of the present disclosure.

FIG. 10 is a side cross-sectional view and a disassembled perspectiveview of a sliding projection in a ceiling protruding-type displayposition adjusting device according to an embodiment of the presentdisclosure.

FIG. 11 is a planar cross-sectional view of a sliding projection in aceiling protruding-type display position adjusting device according toan embodiment of the present disclosure.

BEST MODE

Provided is a ceiling-type display position adjusting device whichemploys a gear structure and enables a display that is positioned abovethe ceiling when the display is not watched to automatically descendfrom the ceiling when the display is watched and automatically adjusts awatching angle of the display.

As illustrated in FIGS. 2 through 11, a protruding-type display Tposition adjusting device according to an embodiment of the presentdisclosure includes a body 100, a retaining bracket 200, a slidingmember 300, an elevating member 400, supports 500, a main link 600, anangle adjusting unit 700, a cover member 800, and a sliding member 900.

The body 100 has a hollow shape having an opened lower portion and isdisposed above the ceiling P as illustrated in FIG. 4.

That is, the body 100 is disposed on top of an indoor space, on theceiling P.

Components which will be described later are mounted on the body 100 asillustrated in FIG. 3.

The retaining bracket 200 retains the body 100 as illustrated in FIG. 4.

That is, the retaining bracket 200 retains the body 100 on the ceilingP, thereby preventing the body 100 from moving or falling.

The sliding member 300 is mounted inside the body 100.

The sliding member 300 is slid in a vertical direction inside the body100 by using the elevating member which will be described later and asillustrated in FIG. 3 to thereby elevate the display T above the ceilingP when the display T is not watched or lower the display T below theceiling P when the display T is not watched.

Sliding of the sliding member 300 in the body 100 will be described indetail later.

The elevating member 400 slides the sliding member 300 in the body 100.

That is, the elevating member 400 moves the sliding member 300 into thebody 100 or below the body 100 to locate the display T above or belowthe ceiling P.

The elevating member 400 includes a lead screw 410, an elevating unit420, a main motor 430, and a protection tube 440.

An upper end of the lead screw 410 is rotatably coupled inside the body100.

That is, the upper end of the lead screw 410 is rotatably coupled to anupper end of the body 100 such that the lead screw 410 is arrangedinside the body 100 in a vertical direction as illustrated in FIG. 3 andinserted into the body 100 to be arranged in the sliding member 300 thatis being slid.

The elevating unit 420 is coupled to an upper end of the sliding member300 to move up and down in a vertical direction via rotation of the leadscrew 410 as illustrated in FIG. 3.

In more detail, the elevating unit 420 is screw-coupled to the leadscrew 410 to be coupled to the upper end of the sliding member 300 andmoves up and down in a vertical direction along the lead screw 410.

The elevating unit 420 lifts up the sliding member 300 via rotation ofthe lead screw 410 as illustrated in FIG. 3(a) such that the display Tis disposed above the ceiling P as illustrated in FIG. 4(a) or lowersthe sliding member 300 as illustrated in FIG. 3(b) such that the displayT is disposed below the ceiling P as illustrated in FIG. 4(b).

The main motor 430 rotates the lead screw 410.

That is, as illustrated in FIG. 3, the main motor 430 is coupled to theupper end of the lead screw 410 that is rotatably coupled to an upperportion of the body 100, thereby rotating the lead screw 410 and thusallowing the elevating member 400 to move up and down in a verticaldirection.

In the elevating member 400, the lead screw 410 is rotated via rotationof the main motor 430 and the elevating unit 420 moves up and down alongthe lead screw 410, and accordingly, the sliding member 300 is slid in avertical direction to move the display T upwardly or downwardly withrespect to the ceiling P.

By configuring the elevating member 400 to include the lead screw 410,the elevating unit 420, and the main motor 430, installation may beeasily performed, and the display T may be easily moved above or belowthe ceiling P.

In the present embodiment, the elevating member 400 includes the leadscrew 410, the elevating unit 420, and the main motor 430. However,unlike the present embodiment, the elevating member 400 may also includeother components as long as the elevating member 400 is capable ofsliding the sliding member 300.

Meanwhile, the protection tube 440 has a hollow shape into which thelead screw 410 is inserted, as illustrated in FIG. 3; one side of theprotection tube 440 is mounted on the elevating unit 420, and the otherside thereof is mounted at a lower portion of the sliding member 300.

The protection tube 440 is moved up and down along with the slidingmember 300 and the elevating unit 420 to surround the lead screw 410protruding below the elevating unit 420.

As the protection tube 440 surrounds the lead screw 410 protruding belowthe elevating unit 420, lubrication oil coated on the lead screw 410 maybe prevented from falling to the outside and piling of foreignsubstances may be prevented.

The supports 500 are coupled under the sliding member 300 on both, leftand right sides as illustrated in FIGS. 3, 6, and 7.

The supports 500, to which the angle adjusting unit 700 and the mainlink 600 which will be described later are coupled as illustrated inFIG. 3, rotate the main link 600 to support a watching angle of thedisplay T coupled to the main link 600.

A rear portion of the main link 600 is rotatably coupled between thesupports 500 via a hinge shaft 601, and the display T is mounted at afront portion thereof.

That is, as the rear portion of the main link 600 is rotatably coupledbetween the supports 500 via the hinge shaft 601 as illustrated in FIGS.6 and 7, the front portion of the main link 600 is rotated about thehinge shaft 601 in a vertical direction to adjust a watching angle ofthe display T mounted at the front portion thereof.

The angle adjusting unit 700 rotates the main link 600 about the hingeshaft 601 to adjust an angle of the display T mounted at the frontportion of the main link 600.

That is, the angle adjusting unit 700 rotates the main link 600 movedbelow the ceiling P via the elevating member 400 to adjust a watchingangle of the display T as illustrated in FIG. 8(b).

The angle adjusting unit 700 includes a rotational motor 710, a worm720, a worm gear 730, a driving gear 740, and a driven gear 750.

The rotational motor 710 is mounted between the supports 500 asillustrated in FIGS. 6 and 7.

Also, the worm 720 is connected to a rotational shaft of the rotationalmotor 710 to be rotated.

The worm gear 730 is engaged with the worm 720.

A rotation rate of the rotational motor 710 is reduced by the worm 720and the worm gear 730.

In addition, as will be described later, a reverse rotation of thedisplay T due to the weight thereof is prevented by the worm 720 and theworm gear 730.

The driving gear 740 is mounted on a same axis as the worm gear 730 soas to be rotated therewith.

That is, the driving gear 740 is rotated on the same axis as the wormgear 730 so as to be rotated in a state in which a rotation rate of thedriving gear 740 is reduced by the worm 720 and the worm gear 730.

The driven gear 750 is mounted on an outer circumference of the rearportion of the main link 600, which is hinge-coupled to the supports500, so as to be engaged with the driving gear 740.

That is, the driven gear 750 is mounted at the rear portion of the mainlink 600 to rotate, about the hinge shaft 601, the rear portion of themain link 600, which is hinge-coupled between the supports 500 via thehinge shaft 601.

When the sliding member 300 is lowered via the elevating member 400 suchthat the display T protrudes below the ceiling P as illustrated in FIG.8(a), the angle adjusting unit 700 adjusts the watching angle byrotating the display T, as illustrated in FIG. 8(b).

That is, when the rotational motor 710 is rotated, a rotation rate ofthe driving gear 740 is reduced via the worm 720 and the worm gear 730,and the driven gear 750 engaged with the driving gear 740 is rotatedaccordingly as illustrated in FIG. 7(a), and the angle adjusting unit700 rotates the rear portion of the main link 600 about the hinge shaft601 as illustrated in FIG. 7(b) to thereby adjust an angle of thedisplay T mounted at the front portion of the main link 600.

As described above, via the angle adjusting unit 700 consisting of theworm 720 and the worm gear 730, the rotational motor 710 is made to moveslowly by reducing a rotation rate of the rotational motor 710, and achange in the watching angle of the display T during a reverse rotationof the rotational motor 710, that is, when the rotational motor 710 isstopped, due to the weight of the display T, is prevented.

The cover member 800 is mounted at the lower portion of the slidingmember 300 to surround the supports 500 and the angle adjusting unit 700as illustrated in FIGS. 2, 5, 6, and 9.

A cut-off portion 801 is formed in the cover member 800 such that afront end of the main link 600 is protruded to be rotatable, that is, afront portion of the main link 600 is vertically movable.

By configuring the cover member 800 as described above, the rear of eachof the angle adjusting unit 700, the supports 500, and the main link 600included therein are not exposed, thereby maintaining the aestheticsense and minimizing penetration of foreign substances.

Meanwhile, as illustrated in FIGS. 10(a) and 11, a plurality of slidinggrooves 101 are vertically formed in the body 100, and a plurality ofcoupling holes 301 are formed in the sliding member 300 along thesliding grooves 101.

Also, the sliding projection 900 is inserted into and coupled to thecoupling hole 301 to slide along the sliding grooves 101.

That is, a plurality of sliding projections 900 are coupled to thecoupling holes 301 and slide along the sliding grooves 101 formed in thebody 100 to facilitate sliding of the sliding member 300 in the body 100described above.

The sliding projection 900 includes a sliding portion 910 and a couplingportion 920 as illustrated in FIGS. 10 and 11.

The sliding portion 910 protrudes from the sliding member 300 to slidealong the sliding grooves 101 as illustrated in FIGS. 10(a) and 11.

An inclined surface 911 that is inwardly titled from an external surfacethereof is formed at an edge of an outer circumference of the slidingportion 910 as illustrated in FIGS. 10 and 11.

When the sliding member 300 including the plurality of slidingprojections 900 is lifted after being slid and lowered from the body100, the inclined surface 911 is used to facilitate sliding of thesliding portion 910 by allowing the sliding portion 910 to be insertedwithout being caught by the sliding grooves 101.

Also, the coupling portion 920 protrudes from the sliding portion 910 tobe coupled to the coupling hole 301 as illustrated in FIGS. 10 and 11.

A protrusion 921 that is inserted into the coupling hole 301 and caughton an edge of an outer circumference of an inner side of the couplinghole 301 is formed at an end of the coupling portion 920 as illustratedin FIGS. 10(b) and 11.

The protrusion 921 ensures coupling of the sliding projection 900coupled to the coupling hole 301 to prevent the sliding projection 900from detaching.

By configuring the sliding projection 900 including the sliding portion910 and the coupling portion 920 as described above, as a plurality ofsliding projections 900 are included, resistance due to frictionoccurring during sliding of the sliding member 900 may be minimized, andwhen the sliding portion 910 of the sliding projection 900 is worn outby friction, the sliding portion 910 may be easily replaced by using thecoupling portion 920.

A process of operating the ceiling protruding-type display positionadjusting device according to an embodiment of the present disclosureconfigured as described above will now be described.

First, the body 100 over which the sliding member 300 is slid to beplaced thereon is mounted such that the display T is placed above theceiling P as illustrated in FIG. 4(a).

When watching the display T, as the main motor 430 is rotated asillustrated in FIG. 3, the elevating unit 420 is lowered along with thelead screw 410 to lower the sliding member so that the display Tarranged below the sliding member is lowered down below the ceiling P tocome into sight as illustrated in FIG. 4(b).

When the display T is lowered below the ceiling P as above, asillustrated in FIG. 7, the main link 600 is rotated using the angleadjusting unit 700 to adjust an angle of the display T as illustrated inFIG. 8(b) to make it easy to watch the display T.

When the watching is ended, on the other hand, the reverse process isperformed and the display T is placed above the ceiling P and is not insight in an indoor space.

As described above, via the elevating member 400 and the angle adjustingunit 700, when the display T is not watched, the display T is maintainedabove the ceiling P, and when the display T is watched, the display Tmay automatically descend from the ceiling P to allow watching and thewatching angle of the display T may be automatically adjusted.

The ceiling protruding-type display position adjusting device accordingto the present disclosure is not limited to the above-describedembodiment, and may be modified in various manners within the scope ofthe present disclosure.

INDUSTRIAL APPLICABILITY

The ceiling-type display position adjusting device according to thepresent disclosure, including a gear structure, locates the displayabove the ceiling when the display is not watched and lowers the displaybelow the ceiling when the display is watched and even automaticallyadjusts a watching angle of the display.

The invention claimed is:
 1. A ceiling-type display position adjustingdevice employing a gear structure and comprising: a body having a hollowshape having an opened lower portion and arranged above a ceiling; aretaining bracket retaining the body; a sliding member that is mountedinside the body and slidable downward below the ceiling; an elevatingmember sliding the sliding member downward below the body; supportscoupled under the sliding member on left and right sides; a main linkhaving a rear portion rotatably coupled between the supports via a hingeshaft and a front portion at which a display is mounted; and an angleadjusting unit rotating the main link about the hinge shaft to adjust anangle of the display, wherein the elevating member slides the slidingmember in the body in a vertical direction to move the display above orbelow the ceiling, and the angle adjusting unit rotates the main linkthat is moved below the ceiling via the elevating member to adjust awatching angle of the display, wherein the angle adjusting unitcomprises: a rotational motor; a worm rotated via the rotational motor;a worm gear that is engaged with the worm; a driving gear that ismounted on a same axis as the worm gear to be rotated with the wormgear; and a driven gear that is mounted on an outer circumference at therear portion of the main link, which is hinge-coupled to the supports,so as to be engaged with the driving gear, wherein when the rotationalmotor is rotated, a rotation rate of the driving gear is reduced via theworm and the worm gear, and the driven gear engaged with the drivinggear is rotated accordingly, and the angle adjusting unit rotates therear portion of the main link about a hinge shaft to thereby adjust theangle of the display mounted at the front portion of the main link andprotruding below the ceiling, wherein a plurality of sliding grooves arevertically formed in the body, wherein a plurality of coupling holes areformed in the sliding member along the sliding grooves, wherein theceiling-type display position adjusting device further comprises asliding projection that is inserted into and coupled to each of theplurality of coupling holes to slide along the sliding grooves, andwherein the sliding projection comprises: a sliding portion protrudingfrom the sliding member to slide along the sliding grooves andcomprising an inclined surface that is inwardly titled from an externalsurface thereof at an edge of an outer circumference thereof; and acoupling portion protruding from the sliding portion to be coupled tothe coupling holes and having a protrusion at an end of the couplingportion, wherein the protrusion is inserted into the coupling holes andcaught on an edge of an outer circumference of an inner side of thecoupling holes.
 2. The ceiling-type display position adjusting device ofclaim 1, further comprising a cover member having a cut-off portionallowing a front end of the main link to protrude and thus the main linkto be rotatable, the cover member being mounted at a lower portion ofthe sliding member to surround the supports and the angle adjustingunit.
 3. The ceiling-type display position adjusting device of claim 1,wherein the elevating member comprises: a lead screw, an upper end ofwhich is rotatably coupled inside the body; an elevating unit coupled toan upper end of the sliding member to move up and down in the verticaldirection by rotation of the lead screw; and a main motor rotating thelead screw, wherein when the main motor is rotated, the lead screw isrotated, and as the elevating unit moves up and down along the leadscrew, the sliding member slides in the vertical direction to move thedisplay upwardly or downwardly with respect to the ceiling.
 4. Theceiling-type display position adjusting device of claim 3, furthercomprising a protection tube having a hollow shape into which the leadscrew is inserted, wherein one side of the protection tube is mounted onthe elevating unit and the other side of the protection tube is mountedat a lower portion of the sliding member such that the protection tubeis moved up and down along with the elevating unit to surround the leadscrew protruding below the elevating unit.
 5. A ceiling-type displayposition adjusting device employing a gear structure and comprising: abody having a hollow shape having an opened lower portion and arrangedabove a ceiling; a retaining bracket retaining the body; a slidingmember that is mounted inside the body and slidable downward below theceiling; an elevating member sliding the sliding member downward belowthe body; supports coupled under the sliding member on left and rightsides; a main link having a rear portion rotatably coupled between thesupports via a hinge shaft and a front portion at which a display ismounted; an angle adjusting unit rotating the main link about the hingeshaft to adjust an angle of the display; and a cover member having acut-off portion allowing a front end of the main link to protrude andthus the main link to be rotatable, the cover member being mounted at alower portion of the sliding member to surround the supports and theangle adjusting unit, wherein the elevating member slides the slidingmember in the body in a vertical direction to move the display above orbelow the ceiling, and the angle adjusting unit rotates the main linkthat is moved below the ceiling via the elevating member to adjust awatching angle of the display.